What is the difference between conventional oil and full synthetic oils?
Surprise I just drained the jeep 2.7 merz. diesel the synthetic oil was just as black and bad as it gets. I think part it's the dam small oil pans on these engines. That's only like 77 hrs. I wonder what is going on to get the oil so dirty. I have had my mechanic doing the oil changes so I didn't know what the other changes looked like. The recommended is 12,000 miles /60 = 200 hrs. With oil like I am changing I doubt the engine would last very long.
Like I say 100 hrs. the heck with recommendation. I will probably use 3000 miles / 60 = 50 hrs. that because of the small oil pan 6.4 quarts. That's what we try on the 5.9 Cummings 7 quarts 3000 miles and that is 15/40 Delo non synthetic oil and it still looks good when it's changed. You would think that with this ULL sulfur diesel that we would see some improvement in the drain oil condition.
So I pose the question again what is the real difference in dino-petro oil and synthetic, how much if any dino-petro oil is in synthetic and is it just the additive package in the synthetic oil?
Darryl,
The difference in dino-petro oil and a full synthetic is that dino-petro oil (conventional oil) is pumped from the ground. A full synthetic oil is engineered and formulated in the lab, and is not pumped from the ground. The lube engineers and lab techs take a molecule from grain, a molecule from a fatty acid and a molecule from propane and depending on the application formulate a specific lube molecule similar to a hydrocarbon molecule. The big advantage to a full synthetic oil is it contains no impurities like conventional oil. Conventional oil that is pumped from the ground contains impurities like: paraffin wax, sulfur molecules, nitrogen molecules, tars, and other items that are not desirable in a lubricating oil.
The paraffin is what gives conventional oil the poor cold flow properties. In order to get the conventional oil to flow, a lot of viscosity improver additives have to be added. A conventional 15W-40 diesel oil will flow down to around -18 to -24 degrees below zero. A full synthetic diesel oil like AMSOIL will flow down to -48 degrees below zero.
By being a pure base stock free of impurities like sulfur and nitrogen, the oil can be ran longer. It is more resistant to acid formation, oxidation and nitration tendencies. It will handle more heat, and will not coke or form carbon like conventional oils.
There are many more differences I could cover. If you would like I can scan in some of my training literature and handouts and email them to you. After reading through them you can call me or email me with any questions.
Be careful as there are a lot of hydro-cracked and iso-dewaxed conventional oil out on the market stating they are a full synthetic. Some liberal judge allowed this to happen. Ask your lube rep what base oil category his oils are. If they are a Group 1 base oils are the least refined. While some automotive oils use these stocks, they are generally used in less demanding applications. Group 2 base oils are common in mineral based engine oils. They have fair to good performance in most areas. They are conventional (dyno) oils. Group 3 base oils are highly refined mineral oils. Although they are not chemically engineered, they do offer improved performance in a wide range of areas. By definition, they are considered a synthesized material and can be used in the production of synthetic and semi-synthetic lubricants. Group 4 oils are polyalphaolefins (PAO) which are chemically engineered synthesized base stocks. PAOs offer excellent stability, molecular uniformity and hence improved performance.
On your gear boxes, do they have any yellow metals (bronze bushings)? Does the OEM call for a GL-4 or GL-5 spec gear oil. I'm thinking a 75W-90 would perform fine. If you are having a lot of wear in the gear box and heat, a synthetic gear oil would have a higher film strength to keep the metals apart. AMSOIL offers gear oils in 75W-90, 80W-90, 75W-110, 75W-140, 190 and 250 SAE. AMSOIL has assisted a lot of customers with gear box and differential issues. If you are partial to a particular brand of oil, I would recommend seeing if they offer a fully synthetic product. As for no filtration on the gear boxes, a simple solution might be to install additional magnets that would capture and hold any wear metals. They can be removed during service to see how much wear is occurring and will prevent the wear metals from running around through your gears and bearing. I've done this on gear boxes, transmissions and sumps. You would be surprised what they will catch. When using conventional oils you will find more fine metals on the magnets than when running a good full synthetic oil.
Hopefully I have answered you question somewhat, there are many more areas that PAO oil out perform conventional oils.
Thanks for the questions,
